The increasing demand for Internet-based video and Internet-protocol television (IPTV) has driven the need for efficient and robust networking systems. To meet the bandwidth and quality-of-service (QoS) demands of broadcasting video over the Internet, network developers often rely on multicasting technologies. One particularly useful network technology for simultaneously broadcasting video to a number of consumers is the point-to-multipoint (P2MP) extension of the resource reservation traffic engineering (RSVP-TE) protocol.
P2MP RSVP-TE provides a number of features that are useful in Internet video distribution and IPTV. For example, P2MP RSVP-TE may guarantee QoS through resource reservation, and P2MP RSVP-TE label-switched paths (LSPs) may be explicitly routed for optimal resource usage. Furthermore, P2MP RSVP-TE provides various resilience procedures, such as global repair.
Unfortunately, P2MP RSVP-TE global repair typically involves re-signaling every branch in a P2MP tree, which may place a significant load on an ingress router that is coordinating the global repair. As a result, P2MP LSPs may not utilize many of the features available to point-to-point (P2P) LSPs, such as auto-bandwidth adjustment and secondary LSP provisioning. Furthermore, the global repair procedures of RSVP-TE may make a fast reroute (FRR) event for P2MP LSPs much more expensive than an FRR event for P2P LSPs. What is needed, therefore, is a more efficient and effective mechanism for reconfiguring P2MP LSP trees.